I've been seeing this two or three times : call more than one monster turn 0.
Why ? You can only attack once during this turn. There is no gain from those extra calls.
The most standart play turn 0 is this one : call a monster to the center and attack with it. It is standart for a really good reason : your opponent has only one choice during his turn : attack your monster and start attacking you.
Now let's take a non-standart, and very bad, play : call three size 1s and attack with only one.
What can your opponent do now ? He can destroy the monster in the center, and attack you (just like if you only called one monster this turn), or he can decide to destroy and win through card advantage.
|Reproduction of the situation I faced|
Is there anything you gained from those two additional monsters beeing on the field ? Not at all. But it opens new possibility to your opponent. Those new options may be bad for him, but against a good oponnent, he will not pick them.
We can extand this to a general rule : don't give possibilities to your opponent; don't call/equip monsters/items you won't attack with because they now can be attacked or destroyed by effect; don't leave your center open if you have no items or center shields.
Of course, there are some situations where those are goods ideas (you expect your opponent to Death grip the monster in your center which will open you the opportunity to attack with your item, you call the monster on the left to bait your opponent to not attack it, and so on), but you must have a good reason. Something more convicing than "Because"